Thermometer well for ball-mill type reactors



E. F. T. RICE Aug. 15, 1944.

THERMQMETER WELL FOR BALL-MILL TYPE REACTORS 2 Sheets-Sheet 1 Filed 001;. 6, 1942 IN VEN TOR.

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ATTORNEY Aug. 15, 1944.

E. F. T. RICE THERMOMETER WELL FOR BALL-MIL L TYPE REACTORS Fild Oct. 6, r 1942 2 Sheets-Sheet 2 n 4 G 7 o. 7 /W n mi T T. A M. [w W f Patented Aug. 15, 1944 THERMOMlETER WELL FOR BALL-MILL TYPE REACTORS Edward F. T. Rice, Hamburg, N. Y., assignor to Allied Chemical & Dye Corporation, New York,

N. Y., a corporation of New York Application October 6, 1942, Serial No. 461,016

Claims.

This invention relates to a well for receiving an element indicating temperature or other conditions within a reactor, and, more particularly, to a thermometer well for accommodating a temperature-measuring element with the temperature-sensitive end in contact with or in close proximity to a reaction mass in a rotating reactor of the ball-mill type.

Ball-mill reactors are commonly equipped with thermometer wells accommodating removalbe thermometric devices such as thermocouples, which wells customarily extend through the hollow trunnions for the reactors. To obtain a reasonably reliable measure of the temperature of the reactionmass within the reactor, the end of the well within the reactor has been bent to reach down into the reaction mass and thus to carry the thermometric device as near as possible to the reactants. The end of such well'disposed exteriorlyof the reactor has been rigidly fastened to prevent it from turning in the trunnion with the reactor or with the moving mass within the reactor. In operation, such constructions fail rapidly because sudden vigorous shocks from collisions of the well with the reaction mass or with agitation elements such as balls, bars or the like within the reactor result in substantial injury to or destruction of the well.

It is an object of the present invention to provide an improved form of well for a reactor which minimizes or overcomes the difficulties hereinabove noted encountered in prior constructions. Other objects of the invention will in part be obvious and in part appear hereinafter.

In accordance with this invention a reactor, preierably'of the rotary ball-mill type, is provided with a well one end of which extends into contact with or in close'proximity to the reactants and the other end of which passes through a hollow trunnion of the reactor and is provided exteriorly of the reactor with a bumper or other shock-absorbing element. The well is mounted so that it is free to rotate to describe an are which is limited by stops suitably cushioned to cooperate with the bumper to absorb the shock imparted, for example, by the free-moving heavy elements within the reactor when they impinge upon the well Walls. Thus, shocks and stresses imparted to the well by heavy objects such as the reaction mass, agitator arms or grinding elements within the reactor striking the well walls are dissipated by the bumper and cooperating stops, and thereby injury to the well is generally avoided, and otherwise minimized.

In a preferred embodiment of the invention the bumper is attached to the well by means of a shear pin or other like mechanical device. Should some condition in the reactor develop an unusually large torque-on the well, the shear pin or other mechanical connection between the bumper and well would be broken. By this construction damage to the machine is avoided by the breaking of the shear pin or other mechanical device which by selection of material and dimensions is adjusted to withstand a safe torque on the well, taking into account the materials of construction and design of the machine.

In the preferred embodiment illustrated on the drawings the invention is shown incorporated in a rotary ball-mill type of reactor, and the present description will be confined to this illustrated embodiment of the invention. It will be understood, however, that the novel features and improvements are susceptible to other applications, such, for example, as reactors not equipped with grinding-balls but provided with agitating blades for agitating the reactants, or reactors of the ballmill or other type in which a well is provided for accommodating a device indicating the viscosity of the reaction mass or other conditions within the reactor. Hence, the scope of this invention is notconfined to the embodiment herein described.

In the drawings, Figure 1 is a plan view of a reactor embodying the improved form of well of my invention; Figure 2 is a fragmentary side elevation taken along line 2-2 of Figure 1; Figure 3 is a side view taken along line 3-3 of Figure 1 of a detail, namely, of the end of the bumper and the cooperating stops; and Figure 4 is a fragmentary sectional plan view taken along the line 44 of Figure 2 showing the connection between the bumper arm and well.

Numeral I represents the motor and reducing gear associated with the driving gear 2 mounted on hollow trunnion 3 which, together with hollow trunnion 4, forms an axial support for the reactor 5 which may be of the ball-mill type, i. e. may contain balls, bars or rods (not shown on the drawings in the interests of clarity) which upon rotation of the reactor effect agitation of the reaction mass. Trunnions 3 and 4 are mounted on supports 6. This construction of the mill is conventional and hence no purpose would be served by describing the same in greater detail.

In accordance with this invention a well 1, which may be a heavy walled tube of single or multi-ply construction, extends through hollow trunnion 3 and is bent so that the end 8 thereof, which may be closed as shown in the drawings or open, depending upon the particular temperature-responsive element employed, is disposed in close proximity to or in contact with the reactants in the reactor. Well I is rotatably mounted in the hollow trunnion 3; the mounting may involve a flanged bearing 9 disposed in hollow trunnion 3 and a suitable packing gland constituted of a flanged collar l and packing II held between the bearing 9 and collar l0. Packing ll may be compressed to any desired degree by tightening nuts l2 which determine the position of collar l0 relative to bearing 9.

The other end I3 of well I is mounted in a suitable bearing M which, together with the bearing 9, permits rotary movement of the well- 1. As

shown in detail in Figure 4, to prevent movementof well I along its axis of rotation in bearing M, end l3 of the well is held rotatably in place by a H ring IE on one side, and by a flanged collar l6 which is fixably secured near the end I3 0f the well 1 on the other side of bearing M A bumper arm I1 is mounted on flanged collar l6 and is provided with an opening !8 aligned with an opening [9 in the flanged collar l6 through which shear pin passes to maintain the bumper arm I! in operative engagement with flanged collar l6 and thereby with the well I; Bumper arm I! is kept from sliding on flanged collar It by ring 2 l' which is held firmly in place by a setscrew or other suitable means. V The freeend of bumper arm I! is provided with flat portions [22 padded with'resilient material such as rubber, indicated by reference character 23. This free end of the bumper arm is disposed within a housing 24, the upper and lower portions of which are padded, forming top and bottom stops 25, 25 which limit rotary movement of the bumperarm. Instead of rubber, the housing 24 and the engaging portions of the bumper may be provided with spring cushions or other resilient members.

In. operation, the reactor drum 5, may be charged with reactants and grinding elements, which may be metal balls, to fill about half the volume of the reactor. When the mill is rotated thereactants and the grinding elements strike the well 1 and cause it to rotate in bearings 9, l4. However, the padded portions 22 of bumper arm I! and cooperating stops 25, 26 limit the extent of rotation. For example, the stops 25, 26 may be so disposed that the bumper arm moves through a small arc, viz., about 14. Thus, the shock imparted to the well is dissipated. Should some condition in the reactor develop an unusually large torque on the well, i. e., a torque beyond that for which the shear pin 20 was selected, the shear pin will break, permitting free rotation of the well in bearings 9, l4, thereby avoiding injury to the machine.

It is to be understood that this invention is not restricted to the disclosure otherwise than as defined by the appended claims.

What is claimed is:

1. In a reactor, in combination, a rotary reaction chamber having a hollow trunnion, a well for receiving a temperature-indicating device having one portion extending through said hollow trunnion in close proximity to the reactants, said well being mounted in said hollow trunnion to permit rotary movement thereof, a bumper mounted on the well and stops cooperating with said bumper to dissipate stresses imparted to said well.

2. A ball-mill reactor comprising a rotary reaction chamber having a hollow trunnion, a well extending throughsaid hollow trunnion mounted for rotary movement therein and having one end extending to a point in close prorn'mity to the reactants within the reaction chamber and the other end disposed exteriorly of the reaction chamber, a bumper mounted on the said end exteriorly of the reaction chamber and stopsfor limiting movement of said bumper.

3. A reactor comprising a rotatable drum having tumbling elements therein for mixing and grinding material therein when the drum is rotated, said drum having an axially aligned opening at an end threof, a thermometer well having one end extending through said opening in heat exchanging relation with the reactants in the drum and the other end disposed exteriorly. of

said drum, a bumper yieldably attached to the.

exterior end of said well and stops defining the limits of rotary movement of said bumper.

4. A reactor comprising in combination a rotatable drum, means for rotating said drum, said drum having an axially aligned opening therein, a tubular element rotatably journaled in said axialopening and having an arcuateportion extending into said drum so that the end thereof is brought in proximity to the drum shell, the straight portion of said tubular element extending outside said drum, a bumper arm fixed to said tubular element by a shear pin, and resilient stops limiting movement of said arm.

5. A. reactor comprising in combination a ro-. tatable drum, means for rotating said drum, said drum having an axially aligned opening therein, a tubular element rotatably journaled in said drum opening and having one end extending into said drum in proximity to the drum shell, a bumper arm joined to said tubular element by a yieldable joint, stops to limit the rotary movement of said arm, and means on said arm and said stops to cushion the impact between said bumper and said stops. EDWARD F. T. RICE. 

